An autopsy is planned for Thursday morning, but police are already looking at drugs as a cause after Kelly, 34, was found unresponsive in his home on Monday, Fulton County police Cpl. Kay Lester told the Atlanta Journal Constitution.

Meanwhile, Kelly's mother, Donna Kelly Pratte, released a joint statement with Kris Kross's former record label, So So Def, mourning Kelly's death.

"It is with deep sadness that we announce that our beloved Chris Kelly has passed away on May 1," the statement reads. "To millions of fans worldwide, he was the trendsetting, backwards pants-wearing one-half of Kris Kross who loved making music. But to us, he was just Chris – the kind, generous and fun-loving life of the party."

"Though he was only with us a short time, we feel blessed to have been able to share some incredible moments with him. His legacy will live on through his music, and we will forever love him."

Kelly and Chris Smith were both 13 when music producer and rapper Jermaine Dupri discovered them in an Atlanta mall. Their song "Jump" was a worldwide smash in 1992.